Generally, an oil-in-water cream preparation emulsified with a non-ionic surfactant is prepared by forming an α-gel in which the molar ratio of the non-ionic surfactant and the higher aliphatic alcohol is 1:3 in the system to solidify the cream.
Therefore, in order to stabilize this preparation, a sufficient amount of the α-gel needs to be formed to solidify the cream and prevent creaming; usually, 4 wt % or more of a amphiphilic substance such as a higher aliphatic alcohol and a non-ionic surfactant are blended in the α-gel.
However, when the oil-in-water cream is prepared with the aforementioned method, while the cream is stabilized by the α-gel, which is needed to solidify the cream, its presence gives a heavy sensation at the time of application, making it very difficult to obtain a cream with a refreshing and light sensation during use.
When the blend ratio of the surfactant is reduced for the purpose of improving the sensation during use, the hardness of the system decreases and there is a problem in that it fails to become cream or creaming occurs at high temperatures.
Based on the aforementioned situation, the inventors conducted earnest research to solve said problem and discovered that an oil-in-water emulsion composition with superior stability over time and usability can be obtained by blending in a hydrophilic non-ionic surfactant or hydrophilic anionic surfactant and a higher aliphatic alcohol under specific conditions in the oil-in-water emulsion composition, thus completing the present invention.
The object of the present invention is to provide an oil-in-water emulsion composition which has superior stability over time and offers satisfactory sensations during use.